Connector for insulated wires



Nov. 10, 1964 1. F. MATTHYSSE CONNECTOR FOR INSULATED WIRES Original Filed March 9, 1961 INVENTOR. IRVING F. MATTHYSSE MM FIGS ATTORNEY United States Patent 3,156,762 CONNECTOR FOR INSULATED WIRES Irving F. Matthysse, Danbury, Conn., assignor to Burndy Corporation, a corporation of New York Continuation of application Ser. No. 94,579, Mar. 9, 1961. This application May 31, 1963, Ser. No. 286,102 2 Claims. (Cl. 174-87) My invention relates to connectors and more particularly to electrical connectors wherein a plurality of wire ends may be electrically joined. This application is a continuation of my copending application Serial Number 94,579, filed March 9, 1961 now abandoned.

Normally, in pigtail connections, the wire ends are stripped of their insulation and the exposed ends twisted to form a single conducting mass which is then compressed into a retaining socket.

The present invention is directed to the object of making the electrical connection without stripping the wire ends of their insulation.

I accomplish the foregoing by employing a special metallic screw means within the connector which will cut the insulation in a twisting operation and not only electrically engage the embedded conductors but which will cause the various wires to be electrically connected to each other and to be mechanically secured to the connector.

These and other objects of my invention are accomplished and new results obtained as will be apparent from the devices described in the following specification, particularly pointed out in the claims, and illustrated in the accompanying drawing in which:

FIG. 1 is an end view of an embodiment of my novel connector;

FIG. 2 is a longitudinally sectioned view of the same taken in the plane 2-2 of FIG. 1;

FIG. 3 is a transverse sectional view taken through plane 3-3 of FIG. 2;

FIG. 4 is a longitudinally sectioned view of another embodiment; and

FIG. 5 is longitudinally sectioned view of still another embodiment of my invention.

Referring more in detail to FIGS. 1, 2, and 3 of the drawing, reference numeral 1% designates a rigid metallic connector body having an insulation cover 12 enclosing the same except for the open conductor inserting end 14.

The inner construction includes an inwardly tapered wall 16 having a threaded configuration 18 employing sharp cutting edges.

Extending longitudinally and inwardly from the closed end 20 of the metallic body is a central tapered cutting member 22, provided similarly with sharp cutting edges 24.

If a plurality of insulated and unstripped wires 26 are inserted into the mouth of the connector and the connector is twisted with respect to the wires, the tapered member 22 will separate the wires and force them against the cutting wall 16. As the wires are threaded toward the closed end 20, the cutting threads of both member 22 and the wall 16 will cut through the insulation 28 of each wire and electrically connect the wires to each other. The outer wall of the insulation may be provided with knurling or grooves 29 to facilitate twisting of the connector with respect to the wires.

In FIG. 4, I disclose a member 30 which is machine threaded to the body 32 at end opening 34. The head or" member 30 may be slotted as at 36 to permit a screw driver to enter when the member is to be twisted.

The inner wall 38 of the connector body need not be threaded, as the member 22 alone is capable of cutting through the insulation to electrically connect the conduc- 3,156,762 Patented Nov. 10, 1964 tor wires. It is also possible to make the connector body of hard plastic with only the screw of the cutting metal. Alternately as shown in FIG. 5, the central member may be omitted and cutting edge 18a of wall 16a depended upon to cut through the insulation.

The inner wall may be outwardly tapered as it approaches the closed end of the connector body. This will cause the wires to be spread apart and snubbed by the connector wall it the conductor wires are accidentally pulled. Where cutting edges are provided for the wall and/0r central member, the parts should be made of conductive metal for an efiicient electrical connection.

It will be noted that there is little danger of the central member cutting through the conductor wires, as the tapered helix thread results in a gradual reduction in the depth of cut, as the end of the central member approaches the mouth of the connector.

I can from the devices shown and described produce a connection between insulation covered wires, which is simple and easy to apply. The resultant connection may be completely insulated with no metal exposed. If the head of the screw in FIG. 4 is insulation covered, the same Would be true of this embodiment.

The invention may be incorporated in a terminal connector as shown, or in an end to end connector.

I have thus described my invention, but I desire it understood that it is not confined to the particular forms or uses shown and described, the same being merely illustrative, and that the invention may be carried out in other ways without departing from the spirit of my invention, and, therefore, I claim broadly the right to employ all equivalent instrumentalities coming Within the scope of the appended claims, and by means of which, objects of my invention are attained and new results accomplished, since the particular embodiments herein shown and described are only some of the many that can be employed to attain these objects and accomplish these results.

I claim:

1. A connector engaging and electrically interconnecting a plurality of insulated wire ends, comprising: a rigid conductive connector body member; an outer insulating cover member on said body member; said body member having an open conductor receiving end and an inner conductor receiving recess; said recess having an inner wall defining a truncated cone-shape, tapering inwardly from a relatively large diameter proximate said conductor receiving end to a lesser diameter remote therefrom; a conductive cone shaped insulation cutting member coaxially supported within said recess, tapering from a given diameter remote from said conductor receiving end to a lesser diameter proximate said conductor receiving end; said cutting member being received in the center of a plurality of said wire ends inserted into said recess in bundle form, said cutting member and said recess inner wall each being provided with helical threads having sharp cutting edges engaging and advancing the wire ends into the said recess as the said body member is rotated relative to the wire axes; the sharp threads of said cutting member extending through the insulation and electrically engaging the conductors in each of said plurality of wires to form a common electrical connection therebetween.

2. A connector engaging and electrically interconnecting a plurality of insulated wire ends, comprising: a rigid connector body member; said body member having an open conductor receiving end and an inner conductor receiving recess; said recess having an inner wall defining a truncated cone-shape, tapering inwardly from a relatively large diameter proximate said conductor receiving end to a lesser diameter remote therefrom; a conductive, insulation cutting contact member, coaxial with and rotatably mounted on said body member within said recess, said 3,1 3 cutting mem er having a cone shaped portion tapering from a given diameter remote from said conductor receiving end to a lesser diameter proximate said conductor receiving end; said Come shaped portion being provided with helical threads having sharp cutting edges engaging and advancing each of said wire ends into said recess as the cutting member is rotated relative to the Wire axes; the said sharp threads extending through the insulation and electrically contacting the conductors of each of said Wires to form a common electrical connection therebetween.

Retereaees Cited in the file of this patent UNITED STATES PATENTS FOREIGN PATENTS France July 19, 

1. A CONNECTOR ENGAGING AND ELECTRICALLY INTERCONNECTING A PLURALITY OF INSULATED WIRE ENDS, COMPRISING: A RIGID CONDUCTIVE CONNECTOR BODY MEMBER; AN OUTER INSULATING COVER MEMBER ON SAID BODY MEMBER; SAID BODY MEMBER HAVING AN OPEN CONDUCTOR RECEIVING END AND AN INNER CONDUCTOR RECEIVING RECESS; SAID RECESS HAVING AN INNER WALL DEFINING A TRUNCATED CONE-SHAPE, TAPERING INWARDLY FROM A RELATIVELY LARGE DIAMETER PROXIMATE SAID CONDUCTOR RECEIVING END TO A LESSER DIAMETER REMOTE THEREFROM; A CONDUCTIVE CONE SHAPED INSULATION CUTTING MEMBER COAXIALLY SUPPORTED WITHIN SAID RECESS, TAPERING FROM A GIVEN DIAMETER REMOTE FROM SAID CONDUCTOR RECEIVING END TO A LESSER DIAMETER PROXIMATE SAID CONDUCTOR RECEIVING END; SAID CUTTING MEMBER BEING RECEIVED IN THE CENTER OF A PLURALITY OF SAID WIRE ENDS INSERTED INTO SAID RECESS IN BUNDLE FORM, SAID CUTTING MEMBER AND SAID RECESS INNER WALL EACH BEING PROVIDED WITH HELICAL THREADS HAVING SHARP CUTTING EDGES ENGAGING AND ADVANCING THE WIRE ENDS INTO THE SAID RECESS AS THE SAID BODY MEMBER IS ROTATED RELATIVE TO THE WIRE AXES; THE SHARP THREADS OF SAID CUTTING MEMBER EXTENDING THROUGH THE INSULATION AND ELECTRICALLY ENGAGING THE CONDUCTORS IN EACH OF SAID PLURALITY OF WIRES TO FORM A COMMON ELECTRICAL CONNECTION THEREBETWEEN. 